1. Field of Invention
The present disclosure generally relates to surveillance systems, and particularly to pan-tilt-zoom (PTZ) presets control analytics configuration.
2. Description of Related Art
Closed-circuit television (CCTV) is often used for video surveillance systems, for example, to provide security for a wide range of businesses or homes. In order to reduce data transfer on a digital CCTV network and the amount of activity that requires human surveillance, modern CCTV systems process video streams and video storage on the basis that parts of an area being monitored may be blocked. Examples of blocked areas include a privacy zone or an area in the field of view that is beyond the perimeter being protected. Processing may also be restricted depending on certain types of activity that should be detected, for example, human activity in a certain area.
A system installer typically configures the blocked area at the time of installation, for example, using an application running on a personal computer (PC). The blocked area may be defined using a simple user-interface such as drag-and-drop shapes and lines using a computer mouse. A set-up step may also include scaling a scene so that it is simpler to discern a human over a broader depth of field. In both cases, the set-up is relatively simple on fixed cameras. However, on pan-tilt-zoom (PTZ) cameras, in which the direction and field of view varies depending on the position of the camera at any instant, set-up and operation become a more challenging problem.
Most modern PTZ and dome cameras include an algorithm to maintain the privacy zone blocking as a camera moves position, but the privacy zone prevents all information from being processed within the blocked region. More sophisticated modern video analytics algorithms may require processing of a human but not a vehicle in a particular area, for example, or may require different analytics functions depending on the time of day or day of week. U.S. Patent Application Publication No. US 2005/0157169 also describes a surveillance system configured for blocking zones.
PTZ cameras are also used in remote, virtual guard tour applications, wherein a sequence of cameras or camera positions are monitored periodically or pseudo-randomly to emulate a traditional tour by a security guard. In many cases, PTZ cameras will be used with their positions in certain pre-set locations where the monitored location is of interest. However, many of the possible pan, tilt and zoom combinations may contain no useful information. In addition, there is a general trend to move more of the image processing away from centralized server architecture to do more of the analysis in the cameras themselves.